The invention relates to
direactive mesogenic compounds or mixtures thereof obtainable by
a) treating a mesogenic diol of formula I,
HOxe2x80x94MGxe2x80x94OHxe2x80x83xe2x80x83(I)
xe2x80x83in which
MG is a mesogenic group,
with a mixture of the halides of formula II and III,
X1xe2x80x94(CH2)mxe2x80x94Raxe2x80x83xe2x80x83(II)
X2xe2x80x94(CH2)nxe2x80x94Rbxe2x80x83xe2x80x83(III)
xe2x80x83in which
X1 and X2 are each independently Cl, Br or I,
m and n are different integers between 1 and 20
Ra and Rb are each independently groups selected from
xe2x80x94CH2OH or xe2x80x94CHxe2x95x90CWH
xe2x80x83wherein
W is H, CH3 or Cl,
in the presence of a base, and
b) treating the resulting intermediate
in the case of Ra and Rb being xe2x80x94CH2OH, with a vinyl derivative of formula CH2xe2x95x90CWxe2x80x94(CO)axe2x80x94Oxe2x80x94 or a reactive derivative thereof, in which a is 0 or 1
in the case of Ra and Rb being xe2x80x94CHxe2x95x90CWH with a perbenzoic acid.
The invention furthermore relates to the preparation of such compounds and to their use in electrooptical scattering systems and for the preparation of oriented liquid crystal polymers.
Reactive liquid crystal compounds can be polymerized in situ, whilst in their liquid crystal phase, to give highly crosslinked anisotropic films which can be used, for example, as polarizing beam splitters (see, for example, EP 0,428,213). Reactive liquid crystal compounds have furthermore been proposed for electrooptical scattering systems (see, for example, EP 0,451,905), cholesteric polarizers (e.g. EP 0,606,940) and compensation films for STN displays (e.g. EP 0,423,881).
Reactive liquid crystal diesters of formula 
are mentioned in EP 0,261,712 (n=0), EP 0,331,233 (n=1). Reactive liquid crystal biphenyls of formula 
are disclosed by EP 0,405,713.
The International Patent application WO 93122397 discloses a compound of formula 
These reactive liquid crystalline compounds often exhibit, however, rather high melting points disadvantageous values of the birefringence and comparable narrow mesophase ranges.
In view of the broad range of applications of reactive liquid crystal compounds it was desirable to have available further compounds of this type which fulfill the various requirements such as a reasonably low melting point, a high birefringence, a broad mesogenic range and preferably an enantiotropic nematic range to a high degree.
It was an object of the present invention to provide new reactive liquid crystalline compounds with advantageous properties thus extending the pool of reactive liquid crystal compounds available to the expert. Other objects of the present invention can be taken from the following detailed specification.
The present invention thus relates to reactive mesogenic compounds or mixtures thereof obtainable by treating mesogenic diols of formula I, in particular those having a symmetric structure unit with a mixture of halides of formula II and III and to their use in electrooptical systems of scattering type and for the preparation of oriented liquid crystal polymers. The invention furthermore relates to the preparation of compounds according to formula I.
Preferred embodiments of the present invention are:
a) Composition of direactive compounds comprising at least one compound of each formula IV, V and VI,
R1xe2x80x94(CH2)mxe2x80x94Oxe2x80x94MGxe2x80x94Oxe2x80x94(CH2)nxe2x80x94R2xe2x80x83xe2x80x83IV
xe2x80x83R1xe2x80x94(CH2)mxe2x80x94Oxe2x80x94MGxe2x80x94Oxe2x80x94(CH2)mxe2x80x94R1xe2x80x83xe2x80x83V
R2xe2x80x94(CH2)nxe2x80x94Oxe2x80x94MGxe2x80x94Oxe2x80x94(CH2)nxe2x80x94R2xe2x80x83xe2x80x83VI
xe2x80x83in which MG, m and n have the meaning given, and
R1 and R2 are each independently
xe2x80x94CH2xe2x80x94Oxe2x80x94(CO)axe2x80x94CWxe2x95x90CH2 or

b) Direactive compound or mixture thereof
xe2x80x83in which
mxe2x80x94n greater than 1, in particular 2, 3 or 4.
c) Direactive compound or mixture thereof in which
MG is a mesogenic group of formula VIII,
xe2x80x94(A1xe2x80x94Z1)oxe2x80x94A2xe2x80x94xe2x80x83xe2x80x83VIII
xe2x80x83in which
A1 and A2 are each independently
(a) 1,4-phenylene in which one or two CH groups may be replaced by N;
(b) 1,4-cyclohexylene in which one or two non-adjacent CH2 groups may be replaced by xe2x80x94Oxe2x80x94 or one xe2x80x94CHxe2x80x94 group may be replaced by xe2x80x94C(CN)xe2x80x94;
(c) naphthaline-2,6-diyl;
it being possible that group (a) is substituted by halogen cyano or alkyl, alkoxy or alkanoyl with 1 to 6 C atoms,
Z1 is each independently xe2x80x94COOxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94CH2xe2x80x94CH2xe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94CH2Oxe2x80x94, xe2x80x94OCH2xe2x80x94 or a single bond, and
o is 1, 2 or 3.
d) Direactive compound or mixture thereof in which MG is selected from the structure elements (1) to (6). 
xe2x80x83in which
L is CH3, Cl, F, OCH3 or xe2x80x94COxe2x80x94CH3, and
r is 0, 1, 2 or 4.
e) Direactive compound or mixture thereof in which
n and m are given by the following table:
m 5 5 5 4 4
n 2 3 4 2 3
A further aspect of the present invention is direactive compounds of formula IV A
R1xe2x80x94(CH2)mOxe2x80x94MGxe2x80x94Oxe2x80x94(CH2)nxe2x80x94R2xe2x80x83xe2x80x83(IVA)
in which
R1 and R2 have the meaning given,
m and n are different integers between 2 and 10, and
MG is a mesogenic group, the core of which being symmetrical, preferably a structure element of formula (1), (5) or (6), in particular
direactive compounds of the formula IVA1
xe2x80x83in which
R1, R2,
L and r have the meaning given,
m and n are different integers between 2 and 10, and
t is 0 or 1.
Other aspect of the invention are the polymers prepared by polymerizing a monomer as described above and chemical intermediate compounds or mixtures thereof useful in preparing direactive compounds or mixtures thereof as described above, comprising mesogene-containing molecules, said mesogenes having two side chains attached thereto that contain hydroxyl or vinyl group at the end thereof, said mesogenes and said functional groups being separated by at least two to twenty spacer atoms, wherein both spacer groups have different chain length.
Above and below, the term reactive mesogenic compounds refers to reactive rod-like molecules which may be enantiotropic, monotropic or isotropic, preferably, however, enantiotropic or monotropic.
In the inventive compounds in which MG is a mesogenic group of formula VIII, A1 and A2 can be independently from each other an unsubstituted or a substituted 1,4-phenylene group of formula 
X2, X3, X5 and X6 can be independently from each other H, F, Cl, methyl or CN.
In the following, for the sake of simplicity, the following notation will be used:
Phe. 2 X2 3 X3 5 X5 6 X6 is a 1,4-phenylene group carrying in 2-position the group X2, in 3-position the group X3 etc.; in case X2, X3, X5 and/or X6, denote H, this will not be specified in above notation, i.e. only true substitutions will be listed. Thus Phe, for example, is an unsubstituted 1,4-phenylene group while Phe.2F 5 Cl is a 2-fluoro-5-chloro-1,4-phenylene group. Furthermore, Pyr is pydmidine-2,5diyl, Pyd is pyrdine-2,5diyl and Nap is a naphthalene-2,6-diyl group. The notation Pyr and Pyd in each case include the 2 possible positional isomers.
The compounds according to formula IV comprise 2- and 3-ring compounds (n=1 or 2) of formulae IV2 and IV3:
R1xe2x80x94(CH2)mxe2x80x94Oxe2x80x94A1xe2x80x94Z1xe2x80x94A2xe2x80x94Oxe2x80x94(CH2)nxe2x80x94R2xe2x80x83xe2x80x83IV2
R1(CH2)mxe2x80x94Oxe2x80x94A1xe2x80x94Z1xe2x80x94A1xe2x80x94Z1xe2x80x94A2xe2x80x94Oxe2x80x94(CH2)nxe2x80x94R2xe2x80x83xe2x80x83IV3
In the 3-ring compounds of formula IV3, the ring groups A1 can be chosen independently from each other.
Especially preferred is a smaller group of 2-ring compounds exhibiting the following structures for xe2x80x94A1xe2x80x94Z1xe2x80x94A2xe2x80x94:
xe2x80x94Phe.2CH3xe2x80x94Phexe2x80x94 IV2-1
xe2x80x94Phe.3CH3xe2x80x94Phexe2x80x94 IV2-2
xe2x80x94Phe.2Clxe2x80x94Phexe2x80x94 IV2-3
xe2x80x94Phe.3Clxe2x80x94Phexe2x80x94 IV2-4
xe2x80x94Phe.2CNxe2x80x94Phexe2x80x94 IV2-5
xe2x80x94Phe.3CNxe2x80x94Phexe2x80x94 IV2-6
xe2x80x94Phe.2Cl3Clxe2x80x94Phexe2x80x94 IV2-7
xe2x80x94Phe.2Cl3Fxe2x80x94Phexe2x80x94 IV2-8
xe2x80x94Phe.2Fxe2x80x94Phexe2x80x94 IV2-9
xe2x80x94Phe.3Fxe2x80x94Phexe2x80x94 IV2-10
xe2x80x94Phe.xe2x80x94Phexe2x80x94 IV2-11
xe2x80x94Phe.Fxe2x80x94Napxe2x80x94 IV2-12
xe2x80x94Phe.2Clxe2x80x94Napxe2x80x94 IV2-13
xe2x80x94Phe.Fxe2x80x94Napxe2x80x94 IV2-14
xe2x80x94Phe.3Clxe2x80x94Napxe2x80x94 IV2-15
xe2x80x94Phe.2Fxe2x80x94Pyrxe2x80x94 IV2-16
xe2x80x94Phe.2Fxe2x80x94Pyrxe2x80x94 IV2-17
xe2x80x94Phe.2CH3xe2x80x94Pydxe2x80x94 IV2-18
xe2x80x94Phe.2Clxe2x80x94Pydxe2x80x94 IV2-19
xe2x80x94Phe.Fxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-20
xe2x80x94Phe.3Fxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-21
xe2x80x94Phe.2Clxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-22
xe2x80x94Phe.3Clxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-23
xe2x80x94Phe.2CNxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-24
xe2x80x94Phe.3CNxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-25
xe2x80x94Phe.2Cl3Clxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-26
xe2x80x94Phe.2Cl3Fxe2x80x94CH2CH2xe2x80x94Phexe2x80x94 IV2-27
The 3-ring compounds according to formula IV3 preferably exhibit the following structures for xe2x80x94A1xe2x80x94Z1xe2x80x94A1xe2x80x94Z1xe2x80x94A2: 
In these structures, IV3-a to IV3-d, L1 and L2 denote independently from each other H, xe2x80x94Cl, xe2x80x94F, xe2x80x94CN and C,H2r+1xe2x88x92s and, in particular, xe2x80x94Cl, xe2x80x94F, xe2x80x94CN, xe2x80x94CH3, and/or xe2x80x94C2H5.
Especially preferred are the following patterns:
xe2x80x94Phexe2x80x94Phe.2CH3xe2x80x94Phexe2x80x94 IV3-a-1
xe2x80x94Phexe2x80x94Phe.2Clxe2x80x94Phexe2x80x94 IV3-a-2
xe2x80x94Phexe2x80x94Phe.2CNxe2x80x94Phexe2x80x94 IV3-a-3
xe2x80x94Phexe2x80x94Phe.2Fxe2x80x94Phexe2x80x94 IV3-a-4
xe2x80x94Phexe2x80x94Phexe2x80x94Phexe2x80x94 IV3-a-5
xe2x80x94Phexe2x80x94Phe.2C2H5xe2x80x94Phexe2x80x94 IV3-a-6
xe2x80x94Phexe2x80x94Phe.3CH3xe2x80x94Phexe2x80x94 IV3-b-1
xe2x80x94Phexe2x80x94Phe.3Clxe2x80x94Phexe2x80x94 IV3-b-2
xe2x80x94Phexe2x80x94Phe.3CNxe2x80x94Phexe2x80x94 IV3-b-3
xe2x80x94Phexe2x80x94Phe.3Cxe2x80x94Phexe2x80x94 IV3-b-4
xe2x80x94Phexe2x80x94Phe.3C2H5xe2x80x94 IV3-b-5
xe2x80x94Phe.3Fxe2x80x94Phe.3Clxe2x80x94Phexe2x80x94 IV3-b-6
xe2x80x94Phe.3Fxe2x80x94Phe.3CH3xe2x80x94Phexe2x80x94 IV3-b-7
xe2x80x94Phe.3Clxe2x80x94Phe.3Clxe2x80x94Phexe2x80x94 IV3-b-8
xe2x80x94Phe.3Clxe2x80x94Phe.3CH3xe2x80x94Phexe2x80x94 IV3-b-9
xe2x80x94Phexe2x80x94Phe.2Clxe2x80x94Phe.3Clxe2x80x94 IV3-b-10
xe2x80x94Phexe2x80x94Phe.3Clxe2x80x94Phe.3Clxe2x80x94 IV3-b-11
xe2x80x94Phexe2x80x94Phe.2Clxe2x80x94Phe.2Clxe2x80x94 IV3-b-12
xe2x80x94Phexe2x80x94Phe.3Clxe2x80x94Phe.2Clxe2x80x94 IV3-b-13
xe2x80x94Phexe2x80x94Phe.2CH3xe2x80x94Phe.3Clxe2x80x94 IV3-b-14
xe2x80x94Phexe2x80x94Phe.3CH3xe2x80x94Phe.3Clxe2x80x94 IV3-b-15
xe2x80x94Phexe2x80x94Phe.2CH3xe2x80x94Phe.2Clxe2x80x94 IV3-b-16
xe2x80x94Phexe2x80x94Phe.3CH3xe2x80x94Phe.2Clxe2x80x94 IV3-b-17
xe2x80x94Phexe2x80x94Phe.2Fxe2x80x94Phe.3Clxe2x80x94 IV3-b-18
xe2x80x94Phexe2x80x94Phe.3Fxe2x80x94Phe.3Clxe2x80x94 IV3-b-19
xe2x80x94Phexe2x80x94Phe.2Fxe2x80x94Phe.2Clxe2x80x94 IV3-b-20
xe2x80x94Phexe2x80x94Phe.3F.Phe.2Clxe2x80x94V3-b-21
xe2x80x94Phexe2x80x94Phe.2Clxe2x80x94Phe.3CNxe2x80x94 IV3-b-22
xe2x80x94Phexe2x80x94Phe.3Clxe2x80x94Phe.3CNxe2x80x94 IV3-b-23
xe2x80x94Phexe2x80x94Phe.2Clxe2x80x94Phe.2CNxe2x80x94 IV3-b-24
xe2x80x94Phexe2x80x94Phe.3Clxe2x80x94Phe.2CNxe2x80x94 IV3-b-25
xe2x80x94Phexe2x80x94Phe.2CH3xe2x80x94Phe.3CNxe2x80x94 IV3-b-26
xe2x80x94Phexe2x80x94Phe.3CH3xe2x80x94Phe.3CNxe2x80x94 IV3-b-27
xe2x80x94Phexe2x80x94Phe.2CH3xe2x80x94Phe.2CNxe2x80x94 IV3-b-28
xe2x80x94Phexe2x80x94Phe.3CH3xe2x80x94Phe.2CNxe2x80x94 IV3-b-29
xe2x80x94Phexe2x80x94Phe.3Fxe2x80x94Phe.3CNxe2x80x94 IV3-b-30
xe2x80x94Phexe2x80x94Phe.2Fxe2x80x94Phe.3CNxe2x80x94 IV3-b-31
xe2x80x94Phexe2x80x94Phe.3Fxe2x80x94Phe.2CNxe2x80x94 IV3-b-32
xe2x80x94Phexe2x80x94Phe.2Fxe2x80x94Phe.2CNxe2x80x94 IV3-b-33
xe2x80x94Phexe2x80x94Phe.2Fxe2x80x94Phe.2Fxe2x80x94 IV3-b-34
xe2x80x94Phexe2x80x94Phe.3Fxe2x80x94Phe.3Fxe2x80x94 IV3-b-35
xe2x80x94Phexe2x80x94Phe.2CHxe2x80x94C2H4Phexe2x80x94 IV3c-1
xe2x80x94Phexe2x80x94Phe.2Clxe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3-c-2
xe2x80x94Phexe2x80x94Phe.2CNxe2x80x94C2H4Phexe2x80x94 IV3-c-3
xe2x80x94Phexe2x80x94Phe.2Fxe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3-c-4
xe2x80x94Phexe2x80x94Phe.2C2H5xe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3-c-5
xe2x80x94Phexe2x80x94Phe.2Cl3Fxe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3c-6
xe2x80x94Phexe2x80x94Phe.2Cl3ClC2H4xe2x80x94Phexe2x80x94 IV3-c-7
xe2x80x94Phexe2x80x94C2H4xe2x80x94Phe.5CH3xe2x80x94C2H4Phexe2x80x94 IV3-c-8
xe2x80x94Phexe2x80x94C2H4xe2x80x94Phe.2Clxe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3-c-9
xe2x80x94Phexe2x80x94C2H4xe2x80x94Phe.2CNxe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3-c-10
xe2x80x94Phexe2x80x94C2H4xe2x80x94Phe.Fxe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3-c-11
xe2x80x94Phexe2x80x94C2H4xe2x80x94Phe.2OCF3xe2x80x94C2H4xe2x80x94Phexe2x80x94 IV3-c-12
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.OCOxe2x80x94Phexe2x80x94 IV3-d-1
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.2CH3xe2x80x94OCOxe2x80x94Phexe2x80x94 IV3-d-2
Phexe2x80x94COOxe2x80x94Phe.3CH3xe2x80x94OCOxe2x80x94Phexe2x80x94 IV3-d-3
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.2CH33CH3xe2x80x94OCOxe2x80x94Phexe2x80x94 IV3-d-4
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.2OCH3xe2x80x94OCOxe2x80x94Phexe2x80x94 IV3-d-5
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.2Clxe2x80x94OCOxe2x80x94Phexe2x80x94 IV3-d-6
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.2Fxe2x80x94OCOxe2x80x94Phexe2x80x94 IV3-d-7
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.2F3Fxe2x80x94OCOxe2x80x94Phexe2x80x94 IV3-d-8
xe2x80x94Phexe2x80x94COOxe2x80x94PhePhexe2x80x94 IV3-e-1
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.2FPhexe2x80x94 IV3-e-2
xe2x80x94Phexe2x80x94COOxe2x80x94Phe.3FPhexe2x80x94 IV3-e-3
xe2x80x94Phexe2x80x94COOxe2x80x94PhePhe.2Fxe2x80x94 IV3-e-4
xe2x80x94Phexe2x80x94COOxe2x80x94PhePhe.3Fxe2x80x94 IV3-e-5
xe2x80x94Phe.2Fxe2x80x94COOxe2x80x94PhePhexe2x80x94 IV3-e-6
xe2x80x94Phe.3Fxe2x80x94COOxe2x80x94PhePhexe2x80x94 IV3-e-7
It was observed that the stability of 3-ring compounds wherein one of the 2 groups Z1 is xe2x80x94COOxe2x80x94 or xe2x80x94OCOxe2x80x94 while the other denotes a single bond, can be increased if the compound is laterally di- or higher substituted, particularly di-substituted by xe2x80x94Cl, xe2x80x94F, xe2x80x94CN and/or xe2x80x94CH3. Compounds of this type are preferred.
Especially preferred are further 3-ring compounds where both groups Z1 are either xe2x80x94COOxe2x80x94, or xe2x80x94OCOxe2x80x94 and at least one of the rings A1, A1xe2x80x2 and A2 are at least mono substituted.
In the compounds of formula IV R1 is CH2xe2x95x90CWxe2x80x94COOxe2x80x94CH2xe2x80x94, CH2 xe2x95x90CHxe2x80x94Oxe2x80x94CH2xe2x80x94, 
with W being H, Cl or alkyl with 1-5 C atoms and m being 1-7.
Preferably, R1 and R2 is a vinyl group, an acrylate group, an epoxy group and especially preferred are the following means of R1 and R2: 
with alkyl denoting C1-C3-alkyl and m being 1-5.
The reaction methods mentioned are briefly summarized in the following synthetic tree: 
Certain compounds or mixtures according to the invention are obtainable in a xe2x80x9cone-pot-synthesisxe2x80x9d as outlined in scheme IV: 
Individual compounds of this type can be obtained according to schemes V to VII: 
The reaction schemes mentioned above are to illustrate the invention without restricting it. The expert can choose other reaction methods without any inventive efforts.
In the following and ink the preceding, all percentages given are percentages by weight. Temperatures are given in degrees Celsius.